in fails if release tag points to another tag

[aoldershaw]

GitHub releases can reference an annotated tag, which is a git object that points to another git object. Currently, we assume that the annotated tag points to a commit:

github-release-resource/github.go

Lines 298 to 309 in af189e0

	// Resolve tag to commit sha
	tag, res, err := g.client.Git.GetTag(context.TODO(), g.owner, g.repository, *ref.Object.SHA)
	if err != nil {
	return "", err
	}
	res.Body.Close()
	if *tag.Object.Type != "commit" {
	return "", fmt.Errorf("could not resolve tag %q to commit: returned type is not 'commit'", tagName)
	}

However, an annotated tag can point to another annotated tag (which then points to a commit), which is a case we don't handle. In general, there could be an arbitrarily long chain of tags before resolving to a commit.

example problematic release - https://github.com/opencontainers/runc/releases/tag/v1.0.0-rc90